/**
 * 	 DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *   @author Colin Redmond
 *   Copyright (C) 2011 Colin Redmond
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */

package com.cred.industries.core.util;

import java.util.Random;

/**
 * generates random XX character long session keys based on the symbols String
 */
public final class SessionKey {
	
	static final String symbols = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
	static final int numSymbols = symbols.length();
	static Random rnd = new Random();

	/**
	 * The constructor is private since this is a utility class 
	 * that does not need to be instantiated 
	 */
	private SessionKey() {
		
	}
	
	/**
	 *  generates random XX character long session keys based on the symbols String
	 * @param len number of characters in the generated session key
	 * @return session key
	 */
	public static String createSessionKey(int len) {
		StringBuilder key = new StringBuilder();
		for(int i = 0; i < len; i++) {
			key.append(symbols.charAt( rnd.nextInt(numSymbols) ));
		}
		return key.toString();

	}
}
